bash-2.01$ perl scanall.pl scantst
Benchmark: timing 5 iterations of BIG_REGEX, CODE_REGEX, MANY_REGEXES, NO_REGEX...
 BIG_REGEX: 138 wallclock secs (133.78 usr +  0.96 sys = 134.74 CPU)
CODE_REGEX: 532 wallclock secs (517.61 usr +  2.68 sys = 520.29 CPU)
MANY_REGEXES: 644 wallclock secs (626.63 usr +  2.96 sys = 629.59 CPU)
  NO_REGEX: 176 wallclock secs (170.91 usr +  1.41 sys = 172.32 CPU)
bash-2.01$ p56 scanall.pl scantst
Benchmark: timing 5 iterations of BIG_REGEX, CODE_REGEX, MANY_REGEXES, NO_REGEX...
 BIG_REGEX: 167 wallclock secs (160.56 usr +  2.00 sys = 162.56 CPU) @  0.03/s (n=5)
CODE_REGEX: 171 wallclock secs (166.17 usr +  1.49 sys = 167.66 CPU) @  0.03/s (n=5)
MANY_REGEXES: 241 wallclock secs (232.62 usr +  2.10 sys = 234.72 CPU) @  0.02/s (n=5)
  NO_REGEX: 175 wallclock secs (169.77 usr +  1.34 sys = 171.11 CPU) @  0.03/s (n=5)
bash-2.01$